I don't think that the abuse flows from the lower clergy to the higher. I think that the secular investigation --- the grand juries and so forth --- are likely to start with the lower, and work up to the higher.
Most of the abuse is old news: even the PA AG report was mostly stuff that was already reported in the John Jay report. (Want to know how many cases they found from the last 10 years? Hundreds? Dozens? No: two. That's right, two. And they had already been reported to the authorities by their own dioceses.) What's NEW is the focus on not the abuse itself, but the complicity of the higher-ups in cover-ups and pay-offs.
And possibly, also, there will be a new focus on the exploitation of legally of-age victims --- seminarians and young clerics --- over the age of 18, which makes up the bulk of the disgusting, sacrilegious pile of vice known as the McCarrick case.
The secular prosecutions will be deserved, but ultimately, feckless. They will focus on abuse of minors (and perhaps the newest victim group: “vulnerable persons”), rehash a lot of old stuff, but find some new stuff, and maybe punish a few bishops for covering-up, but the secular authorities will use their prosecutions to:
1. MOST IMPORTANTLY: Deflect from the real cause: the homoclergy network that runs the Church;
2. Climb their way up politically;
3. Further attack the moral authority of the Church;
4. Use civil fines, penalties, judgements, and seizures through forfeiture law to make a few bucks.
It is a necessary step in God’s purging the Church, but it won’t result in a better Church. This step is designed to soften things up for complete civilizational collapse. For the Church, it will begin a long era of worsening persecution. The next step will come after the collapse of our society (To the islamics? I don’t know. Just a guess.) After a long purge, and cleansing of society of the sodomite crime, then the Church will be purified, and will rebuild.